Acute and chronic ethanol administration is known to affect circulating levels of gonadal hormones in adult animals and humans. Since alteration in these hormone levels during the perinatal period can have profound long-term consequences on adult expression of sexually dimorphic behaviors and neuroendocrine function, it is important to determine whether such alterations exist in animals exposed prenatally to ethanol. Preliminary studies suggest that such changes are present in adult animals exposed to ethanol in utero during the last trimester of pregnancy. The studies in this proposal have been designed to integrate both behavioral and endocrinological measures to determine whether the changes which we have observed are associated with ethanol-induced alterations in circulating levels of steroid hormones during the prenatal period. Moreover, the studies are designed to assess whether these long-term changes are due to an effect of ethanol on the organizational or activational aspects of the physiology underlying the adult expression of sexually dimorphic behaviors. The results of these experiments may lead to more efficacious strategies for the treatment of children of alcoholic mothers.